The beneficial drug nicardipine, 1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl)-3,5-pyridinedicarboxylic acid methyl 2-[methyl(phenylethyl) amino] ethyl ester and its pharmaceutically acceptable salts, is a calcium antagonist clinically useful for the treatment of cardiovascular conditions. Nicardipine is clinically useful for treating cardiovascular condition such as ischemia, hypertension, congestive heart failure, cerebrovascular diseases and coronary artery disease. Nicardipine reduces myocardial oxygen demand through coronary vasodilation and it has cardioprotective and vascular antispastic effects. Nicardipine's chemical structure and synthesis are disclosed in The Merck Index. 10th Ed., p 931, (1983). Nicardipine's therapeutic properties are disclosed in a study reported in Clinical Therapeutics. Vol. 10, pp 316 to 325, (1988). The drug was administered in the latter study intravenously for its cardiovascular effects.
In the light of the above presentation, it will be appreciated by the pharmaceutical and medical professions that a considerable need exists for an oral dosage form useful for administering nicardipine and its salts for the management of cardiovascular diseases and for its clinical relevance. The need exists for a dosage form that can deliver the valuable drug nicardipine and its salts at a rate controlled by the dosage form to a patient in critical need of nicardipine cardiovascular therapy. The pressing demand exists also for an oral dosage form that can deliver nicardipine at a controlled rate and at a constant dose per unit time over a prolonged period of time for its beneficial hemodynamic effects, which delivery occurs substantially independent of the variable environment of the gastrointestinal tract. It will be appreciated further by those versed in the dispensing art, that such a novel and unique form that can administer nicardipine in a rate controlled dose over time, and simultaneously provide cardiovascular therapy, would represent an advancement and a valuable contribution to the arts.